Sigil Core - Procedural Spell Seals & Magic Circle Generator for RPG Maker MZ

This plugin does not report on your spells. It draws them.

Add a skill to your database and its magic circle already exists — a unique, animated, hand-drawn-looking seal generated from that skill’s own data. You never open an art program. You never commission a seal. You never draw the twenty-third one.

Derived from the database, not decorated onto it

• Element picks the ink, glow and accent palette
• Damage type picks the core geometry
• Scope arranges the figure — a single core, a split pair, or a ringed formation
• Hit type sets the stroke — solid, heavy, or dashed
• MP and TP cost decide how intricate it gets, so a 4 MP ember reads as a small plain figure and a 48 MP rite reads as a dense one
• The skill id is the seed — the same spell produces the same seal on every machine, every playthrough, forever

Change a skill in the editor and its seal changes with it. That is the whole point: the art is a function of your data, so it can never drift out of sync with it.

Cost you can see

Because complexity is derived from what a spell costs, your players learn to judge a spell before they read a single number. A cantrip should not look like a ritual, and here it doesn’t.

It does not look like RPG Maker

There is no windowskin anywhere in this plugin. The Grimoire uses a custom frame, a custom serif face, a custom layout and a custom selection accent, all drawn procedurally at runtime. The seals inscribe themselves stroke by stroke when you select them, and the two ring layers counter-rotate continuously on a three-pass additive glow.

That claim is not a marketing line — it is enforced by an in-engine check that walks every sprite in the scene looking for stock engine chrome, and that check is itself proven to fire by injecting stock chrome and watching it fail. It only styles its own scene, so installing this does not restyle your menus, your shop or your battles.

Take the generator alone if you want

Three files, cleanly separated. SigilCore generates the figure and touches no drawing code. SigilRender draws it. SigilGrimoire is the optional in-game spellbook scene. If you only want seals inside your own UI, take the first two and call them yourself — the generator returns plain data.

What ships

• Three raw, readable, commented JavaScript files — 1,933 lines, no minification
• One plugin command (open) — there is nothing else to wire up
• 19 parameters, including a per-element palette structure, symmetry and complexity ranges, glow strength, inscription speed, spin speed and supersampling
• No seal art to draw, commission or license — and no art files to ship
• Works on the skills you already have; add one later and it is covered automatically
• Deterministic — no Math.random() in generation, so seals are stable across saves and machines
• Saves carry no sigil cache, so a save stays small and forward-compatible
• No core method overwritten; every patch extends the prototype and calls the saved original

Verified, not asserted

• 39/39 headless tests over the generator’s pure logic
• 19/19 checks inside real RPG Maker MZ — scene reachable, scene painted, art distinct for all 22 seeded spells, save round-trip clean, zero page errors
• 0.17 ms per frame measured warm over 240 frames, against a 16.7 ms budget

Also from CSAF

• Chimera Core — creature genetics, breeding and box storage
• Chimera Battle — type chart, move sets, status and battle AI
• Chimera Field — spawn tables, rarity, variants and a field guide
• Chronicle Core — branching quests, choices, reputation and world state
• Bazaar Core — supply, demand, depleting stock and trade routes
• Verdict Core — investigation, cross-examination and deduction

Made by Corey Gallant and Stephanie Thomason. Code and cover art are AI-assisted; disclosed on this listing.

Other engines: we build editor tooling beyond RPG Maker too — Kinetic UI and Trove for GameMaker, CoreCLR Migration Scanner and Play Compliance for Unity, and Asset Sentinel and Migration Ledger for Unreal. Everything at csaf.itch.io.